Project description:The purpose of this study was to explore the mechanism of aerobic decay of whole-plant corn silage and the effect of Neolamarckia cadamba essential oil on aerobic stability of whole-plant corn silage. Firstly, the dynamic changes of temperature, microbial community and metabolite content after aerobic exposure of whole-plant corn silage were determined, and the main microbial species and mechanism leading to aerobic spoilage of whole-plant corn silage were analyzed. The N. cadamba essential oil was extracted from fresh N. cadamba leaves by steam distillation, and the minimal inhibitory concentration, antibacterial stability and bacteriostatic mechanism of N. cadamba essential oil against undesirable microorganisms in whole-plant corn silage were determined. According to the minimum inhibitory concentration of N. cadamba essential oil on undesirable microorganisms in silage, N. cadamba essential oil was added to whole-plant corn silage to explore the effect of N. cadamba essential oil on the aerobic stability of whole-plant corn silage.
Project description:<p>Inoculation with homofermentative lactic acid bacteria (LAB) effectively enhances the silage quality of forages. Moreover, feeding such LAB-inoculated silage modulates rumen microbiota composition and metabolites, thereby improving ruminant production performance. Nevertheless, the specific mechanism through which LAB inoculants regulate the silage–rumen–mammary gland axis remains unclear.</p><p>Inoculation with homofermentative Lactiplantibacillus plantarum BX62 improved the alfalfa silage quality. Dairy goats fed the BX62 group silage showed significantly higher milk fat content compared to the control group (no inoculation) (P < 0.05). Integrated analysis of silage microbial metabolomics and experimental validation revealed a significant increase in flavonoid content in the BX62 silage. This was attributed to microbial community restructuring and secretion of carbohydrate-active enzymes (CAZymes), which facilitated plant cell wall degradation and flavonoid release. Rumen metagenomic assembly and binning indicated that feeding flavonoid-rich BX62 silage induced the proliferation of flavonoid-degrading microbes and reshaped the rumen microbiota, which resulted in the upregulation of CAZymes and energy metabolic pathways (e.g., ko00620 Pyruvate metabolism), and enhanced fiber degradation and volatile fatty acid (VFA) production in the rumen. Consequently, acetate-dependent milk fat synthesis was promoted in BX62 group goats as showed by the elevated expressions of acetyl-CoA carboxylase 1 (ACC1), fatty acid synthase (FASN) and acyl-CoA synthetase short-chain family member 2 (ACSS2) in mammary gland. Moreover, four milk fat-positively correlated bacteria species (Eggerthellaceae bacterium, Clostridioides difficile, Candidatus Limivicinus sp., and Collinsella aerofaciens) harboring flavonoid-degrading genes proliferated with elevated flavonoid concentrations in the rumen. In vitro trial further confirmed flavonoid degradation capability in both C. difficile and A. equolifaciens (family Eggerthellaceae), and dose-dependent growth promotion in A. equolifaciens. These results demonstrate that silage-derived flavonoids drive rumen microbiome remodeling and promote mammary lipogenesis through a silage-rumen microbiota-mammary gland triad mechanism.</p>
Project description:<p>Inoculation with homofermentative lactic acid bacteria (LAB) effectively enhances the silage quality of forages. Moreover, feeding such LAB-inoculated silage modulates rumen microbiota composition and metabolites, thereby improving ruminant production performance. Nevertheless, the specific mechanism through which LAB inoculants regulate the silage–rumen–mammary gland axis remains unclear.</p><p>Inoculation with homofermentative <em>Lactiplantibacillus plantarum</em> BX62 improved the alfalfa silage quality. Dairy goats fed the BX62 group silage showed significantly higher milk fat content compared to the control group (no inoculation) (<em>P</em> < 0.05). Integrated analysis of silage microbial metabolomics and experimental validation revealed a significant increase in flavonoid content in the BX62 silage. This was attributed to microbial community restructuring and secretion of carbohydrate-active enzymes (CAZymes), which facilitated plant cell wall degradation and flavonoid release. Rumen metagenomic assembly and binning indicated that feeding flavonoid-rich BX62 silage induced the proliferation of flavonoid-degrading microbes and reshaped the rumen microbiota, which resulted in the upregulation of CAZymes and energy metabolic pathways (e.g., ko00620 Pyruvate metabolism), and enhanced fiber degradation and volatile fatty acid (VFA) production in the rumen. Consequently, acetate-dependent milk fat synthesis was promoted in BX62 group goats as showed by the elevated expressions of acetyl-CoA carboxylase 1 (ACC1), fatty acid synthase (FASN) and acyl-CoA synthetase short-chain family member 2 (ACSS2) in mammary gland. Moreover, four milk fat-positively correlated bacteria species (<em>Eggerthellaceae</em> bacterium, <em>Clostridioides difficile</em>, <em>Candidatus Limivicinus</em> sp., and <em>Collinsella aerofaciens</em>) harboring flavonoid-degrading genes proliferated with elevated flavonoid concentrations in the rumen. <em>In vitro</em> trial further confirmed flavonoid degradation capability in both <em>C. difficile</em> and <em>A. equolifaciens</em> (family <em>Eggerthellaceae</em>), and dose-dependent growth promotion in <em>A. equolifaciens</em>. These results demonstrate that silage-derived flavonoids drive rumen microbiome remodeling and promote mammary lipogenesis through a silage-rumen microbiota-mammary gland triad mechanism.</p>
